Scooterotica

I'm upgrading an Italian 125 engine with a sil 175 steel barrel, can I bolt on a 150 head on it without modification or must I absolutely have a 175 head for it to function properly. 175 heads aren't as easily got and I have a few 150's knocking about. Any thoughts would be appreciated

diesel wrote: ↑Wed Oct 18, 2017 2:46 pm I'm upgrading an Italian 125 engine with a sil 175 steel barrel, can I bolt on a 150 head on it without modification or must I absolutely have a 175 head for it to function properly. 175 heads aren't as easily got and I have a few 150's knocking about. Any thoughts would be appreciated

I think you will have too have the 150 head reprofiled or buy another head,MB machine heads.https://www.lambrettaspares.com/spares/ ... ab016.html
Beedspeed sell cylinder heads for a 175 https://www.beedspeed.com/lambretta-cyl ... -1243.html

150 heads are not hard to modify for 175s, but it can be a bit hit and miss. I did mine and it runs OK - whether it would run significantly better with a commercial one is unlikely. I modified mine with a dremel.

The problem is that modern fuels mean there is less leeway compared to old 4 star fuels, and your chances of it being more miss than hit are higher.

Thanks lads

scooter restorations have some Indian 175cc heads for sale in the clearance section for £15
Small blow holes are easy enough to fill with low temperature aluminium brazing rods ....if they are external to the spark plug they are not under compression. Make sure that the threads are ok though

Thanks Johnny I ordered one today, they’re advertised as usable and dirt cheap. I’ll araldite the holes and hope for the best. Thanks for the heads up

diesel wrote: ↑Fri Oct 20, 2017 11:53 pm Thanks Johnny I ordered one today, they’re advertised as usable and dirt cheap. I’ll araldite the holes and hope for the best. Thanks for the heads up

What are they like? Is it useable?

JB Weld is better than Araldite where high temperatures are involved. 5 minute araldite actually softens at quite a low temperature!

They say the head is useable as is but that there's a blowhole in the plug thread, When I get it I will report back to you. I will use JB Weld instead so Minority,thanks

cant be much worse than the full price one I had off them, shocking piece of crap, which is not usually the case with their stuff